I have a Dell system and it will not power on. At one point I returned home after the holiday weekend and found my pc dead. It would not come on. After a while it would power up for a split second and then power down on its own without me trying to power it on. It would do it repeatedly. In this process I was able to press the power button and then it would come on. It went out this time and would not come on. I am hoping it is only the power supply. Does anyone know what it could be because I hoping it is not the motherboard?